Patent Application
20110105829
The present invention relates to medical implants, and more specifically to a novel transcutaneous auditory prosthetic implant system.
A normal ear transmits sounds as shown in
Hearing is impaired when there are problems in the ability to transduce external sounds into meaningful action potentials along the neural substrate of the cochlea 104. To improve impaired hearing, auditory prostheses have been developed. For example, when the impairment is related to operation of the middle ear 103, a conventional hearing aid or middle ear implant may be used to provide acoustic-mechanical stimulation to the auditory system in the form of amplified sound. Or when the impairment is associated with the cochlea 104, a cochlear implant with an implanted stimulation electrode can electrically stimulate auditory nerve tissue with small currents delivered by multiple electrode contacts distributed along the electrode.
Middle ear implants employ electromagnetic transducers to convert sounds into mechanical vibration of the middle ear 103. A coil winding is held stationary by attachment to a non-vibrating structure within the middle ear 103 and microphone signal current is delivered to the coil winding to generate an electromagnetic field. A magnet is attached to an ossicle within the middle ear 103 so that the magnetic field of the magnet interacts with the magnetic field of the coil. The magnet vibrates in response to the interaction of the magnetic fields, causing vibration of the bones of the middle ear 103. See U.S. Pat. No. 6,190,305, which is incorporated herein by reference.
Embodiments of the present invention are directed to an implantable hearing prosthesis for a recipient patient. An implantable receiving coil receives an externally generated communication data signal. An implantable signal processor is in communication with the receiving coil for converting the communication data signal into a transducer stimulation signal. An implantable enclosed acoustic transducer is in communication with the signal processor for converting the transducer stimulation signal into an acoustic signal for generating acoustic vibrational stimulation of one or more hearing structures in the middle ear of the patient. As used herein, the term “acoustic” refers to the propagation of sound through air, as distinguished from mechanical vibration in solid materials.
In further embodiments, the acoustic transducer may specifically be a floating mass transducer. The acoustic transducer may be adapted to float in an operating position without direct attachment to the tympanic membrane or skull bone of the patient, for example, at the end of a tethering lead. Or, the acoustic transducer may be adapted to be fixedly attached, for example to skull bone or to the tympanic membrane.
The acoustic transducer may have a flexible body for generating the acoustic signal. In specific embodiments, the acoustic transducer may be hermetically enclosed or enclosed by a biocompatible membrane.
In specific embodiments, the acoustic transducer may produce a uni-directional acoustic signal or a multi-directional (e.g., bi-directional) acoustic signal. The hearing structures may include the oval window membrane, the round window membrane, and/or one or more ossicles in the middle ear of the patient.
In various embodiments of the invention, an implantable signal delivery baffle is provided to direct acoustical and/or mechanical energy to structures in an ear. The signal delivery baffle contains an implantable enclosed transducer. The baffle may be an open-ended cylinder with a series of folds in the baffle's wall. The structure and composition of the baffle effectively couples acoustic or mechanical energy generated by the transducer to selected ear structures and isolates residual energy from causing high reverse transfer function (“RTF”) levels. The baffle can be tailored to fit the anatomy of the ear. In specific embodiments, the baffle is made of silicone or of titanium and includes a series of folds in the baffle's wall to determine modes of energy propagation. The folds may be aligned perpendicular or parallel to the longitudinal axis of the cylinder or may be twisted about the longitudinal axis of the cylinder.
In other embodiments of the present invention, a probe microphone system is provided that can substantially mitigate problems with sound instrumentation presented by ambient noise in environments, such as operating rooms. A calibrated sound stimulation signal is fed to a transducer that generates acoustic and/or mechanical energy in the middle ear. A disposable baffle is provided that encloses and seals a volume in the middle ear such as a cochlear window or the entire middle ear. A microphone tube conducts sound from the baffle chamber to a microphone. The microphone records sound pressure levels generating an electrical signal that is amplified and fed to an analog-to-digital converter. The output of the converter is read by processing means, such as a computer and compared to expected sound levels. The microphone baffle serves to substantially reduce ambient noise levels, thus allowing accurate measurements.
Various embodiments of the present invention are directed to an implantable hearing prosthesis for a recipient patient using an implantable enclosed acoustic transducer. This directs the acoustic sound signal as vibrational energy closer to the target structure for hearing, the cochlea.
In the embodiment shown in
In other embodiments, though, the acoustic transducer 205 may be adapted to be fixedly attached, for example to skull bone or to the tympanic membrane 102. In such embodiments, the acoustic transducer 205 may produce what is in effect a uni-directional acoustic signal which may vibrationally stimulate just a single hearing structure, or multiple target hearing structures.
The acoustic transducer 205 may specifically be a floating mass transducer, FMT, with a flexible body for generating the acoustic signal. In some embodiments, the acoustic transducer 205 may be hermetically enclosed or enclosed by a biocompatible membrane (e.g., acting as an implantable acoustic speaker).
In preferred embodiments of the invention, an implantable signal delivery baffle is provided to direct acoustical and/or mechanical energy to structures in an ear. The baffle may be an open-ended cylinder with a series of folds in the baffle's wall. The baffle contains an implantable enclosed transducer. The structure and composition of the baffle effectively couples acoustic or mechanical energy generated by the transducer to selected middle ear structures and isolates residual energy from causing high reverse transfer function (“RTF”) levels. The baffle can be tailored to fit the anatomy of the ear.
Probe Microphone with Disposable Baffle
In preferred embodiments of the present invention, a probe microphone system is provided that can substantially mitigate problems for sound instrumentation that are presented by high ambient noise levels in operating rooms. A calibrated sound stimulation signal is fed to a transducer that generates sound in an ear. A disposable baffle is provided that seals a window of the ear or the entire middle ear. A microphone tube conducts sound from the baffle chamber to a microphone. The microphone records sound pressure levels generating an electrical signal that is amplified and fed to an analog-to-digital converter. The output of the converter is read by processing means, such as a computer and compared to expected sound levels. The baffle serves to substantially reduce ambient noise levels, thus allowing accurate measurements.
In various embodiments of the probe microphone system, the baffle 650 may be made of soft, medical grade silicone that seals a window of the ear 652 or the entire middle ear. Other embodiments may employ other materials for the baffle. These baffles may be disposable or reusable. The microphone probe tubes 660 are sterile and may be disposable or reusable.
Although various exemplary embodiments of the invention have been disclosed, it should be apparent to those skilled in the art that various changes and modifications can be made which will achieve some of the advantages of the invention without departing from the true scope of the invention.
This application claims priority from U.S. Provisional Patent Application 61/256,371, filed Oct. 30, 2009; U.S. Provisional Patent Application 61/310,742, filed Mar. 5, 2010; and U.S. Provisional Patent Application 61/319,504, filed Mar. 31, 2010; which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61256371 | Oct 2009 | US | |
| 61310742 | Mar 2010 | US | |
| 61319504 | Mar 2010 | US |
